21980863 has 8 divisors (see below), whose sum is σ = 22435200. Its totient is φ = 21529368.

The previous prime is 21980857. The next prime is 21980897. The reversal of 21980863 is 36808912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21980863 - 2²¹ = 19883711 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21980363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21870 + ... + 22852.

It is an arithmetic number, because the mean of its divisors is an integer number (2804400).

Almost surely, 2^21980863 is an apocalyptic number.

21980863 is a deficient number, since it is larger than the sum of its proper divisors (454337).

21980863 is an equidigital number, since it uses as much as digits as its factorization.

21980863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1421.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 21980863 is about 4688.3753049431. The cubic root of 21980863 is about 280.1226630923.

The spelling of 21980863 in words is "twenty-one million, nine hundred eighty thousand, eight hundred sixty-three".